Silencer



March 19, 1929. H, MAXIM 1,705,528

SILENCER Filed Dec. 1924 ENVENTOR WW b ATTORNEYS Patented Mar. 19, 1929.

UNITED STATES PATENT OFFICE.

Application filed December This invention relates to silencers such as are used for silencing the explosive exhaust noises of large internal combustion engines and the like, and more particularly to that a type of silencer wherein the exhaust gases are conducted through a tubular structure having a'series of expansion char hers formed by a plurality of baille plates.

One object of the invention is to provide an improved silencer of the above type wherein the baflie plates which form the-expansion chambers also serve to provide Venturi-like passageways between the chambers.

- Another object of the invention is to provide an improved silencer which can be easily and quickly disassembled for cleaning purposes or for decreasing or increasing the capacity thereof; 7

In a greatmany instances where-the exhausts of large engines are to be muifled and a large and heavy silencer is required, it happens that the silencer is located in a limited space where it is impossible, because of surrounding structures, to have access to the ends of the silencer for cleaning or disassembling the same a direction of its axis. In such cases it becomes necessaryto dismount the entire silencer or to remove some of the surrounding building or parts of the engine in order to inspect, clean or repair the silencer.

However, with my improved type of construction, this difiiculty is overcome and the silencer may be disassembled and cleaned in a minimum of longitudinal space.

Further objects of the invention are to provide certain improvements tending to insure strength and rigidity of construction; to facilitate the economical quantity production of silencers of large capacity; to render practical the construction of larger silencers which provision is made for varying the capacity thereof; and to provide various other improved features of construction contributing to the production of efiicient and reliable silencers at low manufacturing costs. To the accomplishment of the above and further objects, as will hereinafter appear, the invention consists in the features of con,- struction and in the combination and ar- 5 rangements of the different arts which Wlll be first described and particularly pointed out in the appended claims.

The invention will be ex lained in connection with the accompanying drawings, in which:

1, 1824. Serial No. 753,192.

Fig. l is a lon itudinal section through the -center of the silencer; and

Fig. 2 is a transverse section taken on the line 2-2 of Fig. l.

Iteferring to the drawings :-it will be observed that the silencer comprises the header members 1 and 2 which. are preferably exactly similar in construction, each one ing provided with an axial aperture 3 and with a plurality of small holes adjacent the peri hery thereof, and of a series of intermediate sections 5, 6, 6 and 7.

In the present embodiment of the invention, the left end of Fig. 1 is to be considered the inlet and the right end the exhaust of the silencer. The intermediate sections 5; 6, 6 and 7 are preferably constructed of tubular sheet metal and each one. is provided at both ends with an outer circular iiange 8 which is preferably Welded or otherwise secured thereto. These flanges 8 are provided with a series of holes for a purpose which. will be readily apparent. The section 5, at the inlet end of the silencer, is considerably longer, as shown by the broken lines in Fig. 1, than the remaining sections, in order to provide the larger expansion chamber 9 at the inlet end.

ihe sections 6, 6 and 7 are each provided with a bafile member which preferably consists of an annular plate 10 and a disc 11. The plate 10 is constructed of sheet metal and is provided at its periphery with an inturned flange 12 which is adapted to fit tightly against the inside surface of each respective section 6, 6 and 7 and to be secured thereto by any suitable means such as by a plurality of rivets 13. This plate 10 is also provided with a central aperture 14 having an out-turned flange 15 at the edge thereof. The disc 11 is also preferably constructed of sheet metal but of a somewhat smaller diameter than member 10 and consists of a flat circular piece of metal having a rounded central protuberance 16. The plate 10 and disc 11 are spaced from each other a slight distance in parallel relation forming a narrow annular passageway 20 leading from one side of the section to the other and are secured to each other by any suitable means, such as by a plurality of short tie bolts and spacing collars l7.

, The assembling of the sections 5, 8, 6 and 7 to each other and to the header members 1 and 2 will be readily apparent from the drawlugs, and is accomplished by the series of short tie bolts 19 passing through the apertures in the flanges 8 of each respective header member and sections which abut each other.

It will be observed in the present embodiment that section 7 is slightly longer than the sections 6, 6 but it is understood that section 7 may be exactly similar to the section '6, 6. In the persent instance, by lengthening out this section 7, a somewhat larger expansion chamber is formed at the exhaust end of the silencer which, in actual practice, increases the efliciency of the silencer. V

There is thus formed a tubular silencer having a relatively large expansion chamber 9 at the inlet end thereof and a plurality of'bafile members providing a series of smaller expansion chambers 18, 18 which are connected by narrow annular passageways 20. In use,.the exhaust gases and sound waves enter the expansion chamber 9 where they are allowed to expand and from whence only a portion-of the sound waves escape to the succeeding chambers 19, 19 on' account of the baffle members and the narrow annular passageways 20 through which they are constrained to pass from one chamber to the next succeeding one; These balile members are so constructed that they also form a series of Venturi-like communicating passageways between the successive chambers which, although restricted for the sound waves ofier a minimum of retardation for the esca ing gases due to the well known laws of a enturi passage. It will be observed that the passageway 20 is annular and extends radially from the axis of the silencer whereby its volumetric area while comparatively small at the inlet end adjacent said axis increasesvery rapidly toward the periphery of said silencer. In this way, the sound waves may be trapped eificiently without causing an appreciable amount of back pressure for the engme.

It will also be observed that a new and improved silencer has been constructed which is capableof being assembled and disassembled transversely of the longitudinal axis of same. This is an important feature in the case of large and heav silencers where there is 2. limited amount 0 space in a direction longitudinally of the silencer as it allows the silencer to be easily and quickly disassembled and assembled again for cleaning or renewing the parts of same without disconnecting the whole silencerand the connections of same from the en ne.

he invention has been disclosed herein for illustrative purposes in its preferred embodiment, but it is to he understood that the scope of the invention is defined by the appended claims rather than by the foregoing description.

What I claim is:

1. A silencer comprising, header members and a series of separately removable tubular sections, a lurality of which have individual ballle mem ers secured and wholly confined therewithin intermediate the ends of each of their respective sections, said sections and header members adapted to be assembled and disassembled transversely within a minimum len th of the longitudinal axis of the silencer wit the ends of said sections abutting one another and said header members abutting the ends of the outermost sections, the whole forming a series of intercommunicating expansion chambers, said baflie members being transversely disposed within said sections and comprising an annular plate having a central opening therein secured to its respective tubular section and a disc having a central protu berance projecting into said opening to provide a narrow annular passageway between the chambers, and means to separately secure said sections and header members in assembled relation.

2. A silencer comprising, header members and a series of separately removable tubular sections, a plurality of which have individual bafile embers secured and wholly confined therewithin intermediate the ends of each of their respective sections, said sections and header members adapted to be assembled and disassembled transversely within a minimum length of the longitudinal axis of the silencer with the ends of said sections abutting one another and said header members abutting the outermost sections, the whole forming a series of intercommunicating expansion chambers, said bafile members being transversely disposed within said sections and comprising annular plates secured to their respective tubular sections and having outwardly flaring central openings and discs of 'less diameter than said plates having, rounded central protuberancesprojecting into said openings, said discs being removably secured to said plates and slightly'spaced therefrom in parallel relation to provide a1inular Vonturi-like passageways between said chambers, and means to separately secure said sections and header members in assembled relation.

3. A silencer comprising, header members and a series of separatel removable tubular sections, a plurality of which have individual bafile members secured and whollyconfined therewithin intermediate the ends of each of their respective sections, said sections and header members adapted to be assembled and disassembled transversely within a minimum length of the longitudinal axis of the silencer with the ends of said sections abutting one another and said header members abutting the outermost sections, said baflie members being transversely disposed within said sections and comprising annular plates secured to their respective sections and having outwardly flarin central openings therein and discs of less lameter than said plates secured thereto, said discs having rounded central protuberancesprojecting into said openings, the whole constructed and arranged to form a series of comparatively large cylindrical expansion chambers connected by relatively narrow annular passageways and means to separately secure said sections, header members and baflle members in assembled relation.

4. A silencer comprising header members and a cylindrical casing, a series of bafile members forming a series of intercommunieating expansion chambers, said baifle members being transversely disposed within said casing and. comprising annular plates secured thereto and having outwardly flaring central openings and discs of less diameter than said plates having rounded central protuberances projecting into said openings, said discs being removably secured to said lates and slightly spaced therefrom in paraliel relation to provide annular Venturi-like passageways between said chambers, and means to secure said casing, header members and bafile membersin assembled relation.

5. A silencer comprising header members and a cylindrical casing, a series of baffle members, said bafile members being transversely disposed within said casing and comprising annular plates secured to said casing and having outwardly flaring central openings therein and discs of less diameter than said plates secured thereto, said discs-having rounded central protuberances projecting into said openings, the whole constructed and arranged to form a series of comparatively large cylindrical expansion chambers connected by relatively narrow annular passageways, and means to secure said casing, header members and baflle members in assembled relation.

6. A silencer comprising a cylindrical casing unobstructed exce t for partitions spaced apart along the length of the casing to provide a series of expansion chambers arranged end to end, each partition having an annular passageway of substantially uniform axial depth small in proportion to the depth of the expansion chambers, said axial depth being sufiiciently small to produce adrop in pressure of the gases passing therethrou h, and each passageway opening from one 0 amber near the axis of the cylinder and into the next chamber near the outer wall of the cylinder.

7. A silencer comprising a casing unobstructed except for partition walls spaced apart at intervals longitudinally along the casing and formed to present annular, out- Ward y-directed, Venturi-like passages separating the casing lon itudinally into a $110- cession of expansion c ambers of lar e volume as compared with the volume of t e passa es.

sin testimony whereof I have aflixed my signature.

HIRAM PERCY MAXIM. 

